(1) Field of the Invention
This invention relates to a folding drafting table and the like having means for adjusting the height and means independent of height adjusting means to secure the table-top at a desired angle. In folded position the table-top is substantially parallel to a main frame having a pair of spaced leg portions folded inwardly, the table being relatively compact in the folded position.
(2) Description of the Prior Art
Numerous patents relate to drafting tables, foldable or otherwise, to means for selecting a desired height or angle for the table-top and to foldable tables.
U.S. Pat. No. 3,217,673, issued Nov. 16, 1965 to F. D. Knoblock, discloses a folding typewriter table comprising a U-shaped single piece main frame having two vertical leg portions and a connecting cross-portion at the top, a pair of U-shaped side members, each comprising a lower arm for resting horizontally on a floor and an upper arm substantially parallel thereto for supporting the underside of a table-top, the side members being pivotally connected to vertical portions of the leg portions of the main frame, so that one side member may be pivoted flat against the main frame and the other side member may be folded flat against the one folded side member, a brace extending between the legs of the main frame and a brace extending between the upper and lower arms of each side member, and means for releasably securing said braces in position. The table of this patent provides no means for adjustment of the height thereof, and no means for adjusting the angle of the table-top since it is intended for use only as a typewriter table.
U.S. Pat. No. 3,805,710, issued Apr. 23, 1974 to A. Leshem, discloses a foldable table having a table-top which can be adjustably secured at a selected attitude or tilt. A frame is provided having a pair of spaced parallel leg portions in a common plane, with a side leg supported on each leg portion of the frame for swinging movement between a folded position wherein the side legs are overlapped and generally parallel to the frame and an operative position wherein the legs are perpendicular to the frame. The pivot axis of the side legs are "located in differentially offset relation to the common plane containing the leg portions of the frame." A table-top supporting extension is mounted on each leg portion of the frame for movement between a retracted position and selected elevated positions, with a table-top supported on the extensions for swinging movement between an operative position and a folded position, the table-top in its folded position being parallel to the frame with the side legs interposed and retained between the table-top and the frame. Each leg portion of the frame, and each side leg have extensible supports mounted in coaxial telescoping relation to the legs, and manually operable locks for each leg portion and side leg.
The structural arrangement is therefore such that adjustment of the height of the table-top can be effected only by individual adjustment of four extensible supports and the manually operable lock for each, and adjustment of a desired attitude or tilt of the table-top can be effected only after the height has been adjusted, by further movement of the extensible supports of the leg portions of the frame and the locks for each . It is thus apparent that the means for adjustment are inconvenient and subject to error since there is no correlation among the various extensible supports. Moreover, the overlapped relation of the side legs when in folded position does not provide the most compact package possible.
Other U.S. Patents relating to tables with tiltable surfaces, folding tables, and vertical adjustability of folding tables, include the following:
______________________________________ 3,908,560 2,879,118 3,589,311 3,365,072 3,525,492 3,000,683 3,145,966 2,733,971 3,080,193 2,106,309 2,837,394 3,256,840 3,786,766 986,131 3,247,811 981,114 ______________________________________
It is evident that a genuine need exists for a folding drafting table and the like which provides easy and convenient adjustability of the height of the table-top and easy and convenient adjustability of the tilt or angle of the table-top about a horizontal axis independent of the height adjustment, and which is at the same time capable of being folded into an extremely compact package. To the best of applicant's knowledge such a structure has not previously been disclosed or suggested.